I've installed henkaku, and adrenaline, Vita Shell and a Vita game VPK all on my phat Vita on 3.68, using my official Sony Vita 16gb mem card. I have a 128gb microsd with the sd2vita adapter on the way. Once I have that set up, can I simply transfer what I've already installed over to that microsd? How does that work? Can I use both mem cards at the same time?

I'd rather not have to take out the adapter to play my physical games, so how can I dump my physical games so I can then put them on my microsd and play them from there?

I've installed henkaku, and adrenaline, Vita Shell and a Vita game VPK all on my phat Vita on 3.68, using my official Sony Vita 16gb mem card. I have a 128gb microsd with the sd2vita adapter on the way. Once I have that set up, can I simply transfer what I've already installed over to that microsd?

Yes. Highlight the drive itself in Windows (do not OPEN the drive), copy it somewhere on your PC. Insert the microSD into your computer and paste your previously copied files to it.

Nope. Not for Vita games. The card not mounted as the ux0 drive will only be backup storage while the other card is active. Adrenaline and some emulators have a setting to use that extra drive, but not Vita games.